ethmoidal

{ } a. [ Gr. &unr_; like a sieve; &unr_; sieve + &unr_; from: cf. F. ethmoïde, ethmoïdal. ] (Anat.) (a) Like a sieve; cribriform. (b) Pertaining to, or in the region of, the ethmoid bone. [ 1913 Webster ]

Ethmoid bone (Anat.), a bone of complicated structure through which the olfactory nerves pass out of the cranium and over which they are largely distributed. [ 1913 Webster ]